Hillary Clinton warns of fake news

Investigators return to Russian plane crash site

Investigators return to Egypt's Sinai Peninsula where a Russian airliner crashed over the weekend.

"There is an increasing likelihood that it was a small explosive device in the luggage hold," a senior Australian source has told Fairfax Media while stressing this view was yet to be fully verified.

But the growing firmness of the theory that a bomb was smuggled into the hold was also reflected overnight in the British government's decision to ban checked luggage on return flights from the resort of Sharm el-Sheikh to the UK.

A spokeswoman for Australia's Department of Foreign Affairs said late on Thursday that some Australians were in Sharm el-Sheikh but none had asked for consular assistance.

"We are aware of a small number of Australians registered in the Sharm el Sheikh area. There have been no requests for consular assistance to date. Australian travellers affected by delays to flights from Sharm el Sheikh are advised to contact their airline or travel agent for the latest information on flight disruptions and on airline plans to reschedule departures," she said.

The government is urging Australians to reconsider travel to the South Sinai region.

Foreign Minister Julie Bishop has sent a personal condolence note to her Russian counterpart Sergey Lavrov.

But the Russian and Egyptian government's both continue to describe as premature the assumption that a bomb brought down the plane.

A statement sent out by the Russian embassy in Canberra on Thursday night said that "all commentary about the possible causes of the crash is premature and unfounded".

"Before the Egyptian aviation authorities - the only source of the official information - render their findings public, all hypothetic insinuations in that regard are inappropriate," the statement said.